According to the Vedas, or the main book of basic beliefs of Hinduism, one belief about the Hindu way of life is that four different types (or classes) of people were created from different parts of a god's body.
The caste system organizes all of India's Hindus into hundreds of groups and levels. Each person is born into their caste (level), and that cannot be changed. The only way to alter one's caste is through the cycle of reincarnation, or rebirth. If you do good deeds in your life, when you die, you may be reborn into a higher caste!